Fiber cutter

ABSTRACT

A self-adjusting fiber cutter for cutting lengths of fibers such as glass roving and the like into short lengths. The cutter section of the fiber cutter includes fluidic means for biasing roller means of the cutter section into engagement with another roller means of the cutter section to thereby compensate for wear experienced by the fiber cutter and to facilitate loading and unloading of fibers. The fiber cutter has a low start-up torque to minimize jamming of the fiber cutter at start-up. The pressure roller means of the fiber cutter is eccentrically mounted to compensate for possible inconsistencies in fabrication tolerances between several of the roller means of the fiber cutter.

o United States Patent 11 1 1111 3,763,561 Scharfenberger Oct. 9, 1973FIBER CUTTER 2,719,336 10/1955 Stotler 83/913 x Inventor: James ge3,304,821 2/1967 Matmo et al. 83/913 X Indlanapohs PrimaryExaminer-Andrew R. Juhasz [7 3] Assignee: Ransburg Electro-CoatingAssistant Examiner-James F. Coan Corporation, Indianapolis, Ind.Attorney-Merrill N. Johnson et al.

[22] Filed: Feb. 22, 1972 [57] ABSTRACT [21] PP 9105228313 Aself-adjusting fiber cutter for cutting lengths of fibers such as glassroving and the like into short 152 us. (71 30/128, 30/264, 83/347,lengths The cutter Swim of fiber cutter includes 83/348. 83/913 fluidicmeans for biasing roller means of the cutter 1511 1m. 01 B26b 27/00engagement with amber ro'ler means of 5s 1 Field of Search 83/913 348347 the cutter hereby compensalte for Wear 83/99 343 346 30/128 6perienced by the fiber cutter and to facilitate loading and unloading offibers. The fiber cutter has a low [56] References Cited start-up torqueto minimize jamming of the fiber cutter at start-up. The pressure rollermeans of the fiber UNITED STATES PATENTS cutter is eccentrically mountedto compensate for pos- 3,498,l66 3/1970 Pook 83/913 X Sibleinconsistencies in fabrication tolerances between several of the rollermeans of the fiber cutter.

3,508,461 4/1970 Stream 83/347 X 10 Claims, 4 Drawing Figures PAImmnmsms SHEET 10F 2 PATENTEDUEI ems SHEEI 2 BF 2;

FIBER CUTTER The present invention relates to a self-adjusting fibercutter for cutting fibers such as glass roving and the like into shortlengths and to a fiber cutter having means to facilitate loading andunloading of fibers. More particularly, the invention is directed to aself-adjusting fiber cutter including fluidic means for biasing rollermeans of the fiber cutter into engagement with another roller means ofthe fiber cutter to thereby compensate for wear experienced by the fibercutter and to facilitate loading and unloading of fibers. The fibercutter has a low start-up torque to minimize jamming at start-up. Thepressure roller means of the fiber cutter is eccentrically mounted sothat the shaft carrying the pressure roller means can be positioned asto compensate for possible inconsistencies in fabrication tolerancesbetween the several roller means of the fiber cutter.

It is known to mix cut lengths of glass fibers with plural componentmaterials such as thermosetting and thermoplastic plastics, and inparticular, polyester resin, to reinforce such plastic materials.Polyester resin reinforced with cut lengths of glass fiber is used inboat hulls, car body panels, bathroom fixtures and the like. Polyesterresin reinforced with glass fiber has high chemical and heat resistance,good impact and tensile strength, dimensional stability, stiffness andhardness.

Glass fibers to be cut or chopped into short lengths by a fiber cutterare usually provided as a plurality of continuous lengths of relativelysmall diameter gathered together. The gathered together glass fibers arecalled strands. The diameter of the individual glass fibers is generallyin the range of about 10 X 10 to about 75 X inch, and usually thediameter of the glass fibers is in the range of about 30 X 10' to 60 X10 inch. Generally, there are about 200 glass fibers per strand.However, a strand may have more or less glass fibers depending on, forexample, the diameter of the individual glass fibers. Glass rovingincludes a number of untwisted strands grouped in a bundle to form acontinuous ribbon of multiple strands.

The glass roving supplied from a bundle to a fiber or glass rovingcutter is severed by the action of the cutter section thereof intolengths of about one-half to 2 inches, and preferably into lengths ofabout 1 inch just prior to being mixed with a plural component materialsuch as polyester resin to reinforce the same. Generally, a composite ofpolyester resin and chopped glass roving includes a nominal glasscontent of about 15 to 40 weight percent glass, the remaindersubstantially polyester resin. However, the weight percent of glassroving to plural component material will vary depending on severalfactors including the type of resin used to provide the matrix of thecomposite, the process used to make the composite, and the applicationto which it is desired to put the composite.

A presently available glass roving cutter employed to cut the glassroving into the desired lengths for introduction into a spray ofpolyester resin includes a cutter roller carrying a plurality of rovingcutter blades; the blades are in engagement with a back-up roller havinga resilient surface to thereby provide a nip into which the glass rovingis fed during operation of the roving cutter. A pressure roller engagesthe back-up.roller and feeds the glass roving to the nip. A rovingcutter wherein each of the rollers are fixed relative to one an other isillustrated in United States Letters Pat. No. 2,787,314. The blades ofthe cutter roller press the glass roving against the back-up roller tothereby sever the roving into short lengths called chop. The glass chopis ejected from the roving cutter into resin. A cutter roller typicallyoperates at speeds of up to about 3,000 revolutions per minute.

During operation of a glass roving cutter wherein each of the rollersare fixed relative to one another, the back-up roller experiences weardue to, the heat generated by friction, thereby reducing the cutterpressure between the cutter roller and the back-up roller. Themaintenance of the cutting pressure of the cutter within a given rangeis necessary if the cutter is to provide glass chop of substantiallyuniform length having unfrayed extremities. Glass chop having anon-uniform length and/or frayed extremities is not desirab;e for iteffects the appearance and strength of the composite in which it isused.

United States Letters Pat. No. 3,491,443 discloses a roving cutterwherein the cutter roller is self-adjusting relative to the back-uproller to compensate for wear to thereby provide a substantially uniformcutting pressure during operation of the cutter. The cutter roller isspring biased against a resilient back-up roller to provide asubstantially uniform cutting pressure thereby compensating for wear ofthe back-up roller. United States Letters Pat. No. 3,034,213 shows theuse of a single adjustment screw for adjustably supporting a back-uproller with respect to a cutter roller.

The fiber cutter of the present invention employs fluidic means, such asa plurality of air activated means to bias back-up roller means intoengagement with cutter roller means so as to, among other things,compensate for wear experienced by such roller means during theoperation of the fiber cutter and to facilitate loading and unloading offibers. Further, using fluidic means to bias the back-up roller meansprovides a fiber cutter having relatively low start-up torque tominimize jamming at start-up. Other features and advantages of my fibercutter, such as less cost, ease of repair and adjustment and the likewill be apparent from the following disclosure.

In the drawing:

FIG. I is a perspective view of a fiber cutter according to the presentinvention shown mounted on a multiheaded spray gun;

FIG. 2 is a front sectional view of the fiber cutter with parts thereremoved;

FIG. 3 is a view taken substantially along line 3-3 of FIG. 1 witheccentrically mounted pressure roller means engaged with back-up rollermeans; and

FIG. 4 is a side view of the fiber cutter with selected portions thereofremoved illustrating the preferred position of the roller means of thefiber cutter during the loading and unloading of the fibers.

Referring now to the several FIGURES of the drawing, and particularly toFIG. I, a fiber cutter incorporating the concepts of this disclosure isindicated by the reference numeral 10. The fiber cutter 10 is especiallyadapted to cut glass roving 12 into short lengths. It is to beunderstood that the fiber cutter 10 may be used to cut fibers other thanglass roving into short lengths.

The fiber cutter 10 is shown in cooperative association with spray gun11. The spray gun 11 is shown in dotted lines. The cutter 10 is suitablycarried by the gun 11. As shown in FIG. 3, the cutter 10 chops or cutsglass roving 12 into lengths of cut roving l3, and ejects the cut rovinginto a spray of plural component material (not shown) such as polyesterresin ejected or dispensed from the gun 11. The cut roving l3 and theplural component material are mixed externally of the cutter and the gun11 and are applied to an application surface (not shown) which serves toform the mixture into an article of manufacture. The details of thestructure and function of the spray gun 11 are not disclosed here sincesuch details are discussed in United States Letters Pat. No. 3,399,834.

As shown in FIG. 1, the fiber cutter 10 includes a housing means 14 forsupporting several of the compoennt parts of the fiber cutter. A drivemotor 15 is suitably affixed to a side closure 16 of housing means 14.The side closure 16 and the side closure 17 are used to close oppositeends of the housing means 14 as shown in FIG. 2.

A cavity 18 provided by the cooperative relation between the housingmeans 14 and the side closures 16 and 17 is referred to hereinafter ascutting chamber 18. The housing 14 and the side closures 16 and 17 arefabricated from any suitable structural strong and wear resistantmaterial such as metal and the like.

A back-up roller means 19 and a pressure roller means 20 are suitablycarried between the side closure 16 and the side closure 17. Roving froma glass roving bundle (not shown) is introduced into the cutting chamber18 to the inlet end ofa nip 22 provided by the structural cooperationbetween the back-up roller 19 and the pressure roller 20 as shown inFIG. 3. The roving is discharged from the outlet end of the nip 22between the back-up roller 19 and the pressure roller 20 and fed to anip 23 provided by the structural cooperation between the back-up roller19 and a cutter roller means 24. As the glass roving passes between thebackup roller 19 and the cutter roller 24, it is cut into lengths of cutroving 13 and ejected from an ejection opening 25 of the fiber cutter10. FIG. 3 shows the fiber cutter 10 cutting glass roving 12 intolengths of cut roving 13.

A shaft 26 of the drive motor 15 is suitably connected to and rotatablydrives cutter roller means 24. Cutter roller 24 includes shaft 21suitably journalled in the side closure 17 by bearing means 27. Theshaft 21 is coaxial with the shaft 26 of drive motor 15. The cutterroller 24 is concentrically mounted on and suitably carried by the shaft21 and the shaft 26 so as to be rotated by the drive motor 15. Thecutter roller 24 includesa plurality of cutting blades 29 arranged alongits peripheral surface in circumferentially spaced, paralledrelationship. The cutting blades 29 each have a razor-like cutting edgeprojecting a short distance from surface 30 of the cutter roller 24. Thecutting edge of each of the blades 29 is substantially straight andsuitably carried by the cutter roller in a plane that is at an anglewith the plane of the axis of rotation of the cutter roller 24. Thecircumferential distance between the individual cutting blades 29dictates the length of the cut roving 13 ejected from the fiber cutter10. The cutter roller 24 is fabricated from any structurally strong andrigid material such as rigid plastic, metal and the like.

The back-up roller 19 is concentrically mounted on a stationary shaft 31and rotatable thereon through bearing means 37 and bearing means 38.Opposite ends of the stationary shaft 31 are suitably retained in slots34 and in the side closures 16 and 17 respectively.

One end of the stationary shaft 31 includes a flat section 32, shown inFIG. 4, that engages with flat section 33 of elongated slot 34 in theside closure 16 to prevent rotation of the shaft 31. As shown in FIG. 2,the oppoiste end of the stationary shaft 31 is positioned in elongatedslot 35 in the side closure 17. It should be seen that the shaft 31 canmove in a plane substantially perpendicular to the axis of rotation ofthe back-up roller 19 yet is prevented from undergoing rotationaldisplacement. The degree of movement of the shaft 31 in the planeperpendicular to the axis of rotation of the back-up roller 19 isgenerally dependent on the length of the elongated slots 34 and 35.Preferably, the length of each of the elongated slots 34 and 35 issubstantially the same.

The back-up roller 19 is made of any suitable resilient material such asrubber, polyurethane, or the like. It should be appreciated that whilethe cutter roller 24 is rotatably driven by the drive motor 15, rotationof the cutter roller 24 transmits a driving force to the back-up roller19 by virtue of its frictional engagement with the cutter roller 24 andto the pressure roller 20 by virtue of frictional engagement of thepressure roller with the back-up roller. Although the surface of theback-up roller 19 is illustrated in the drawing as being smooth, it willbecome roughened during operation by engagement with the cutter blade 29of the cutter roller 24.

As shown in FIG. 2, fluidic means 39 and 40 are are used to suitablybias the back-up roller 19 into engagement with the cutter roller 24.Each of the fluidic means 39 and 40 is shown as a pneumatic or aircylinder, although hydraulic cylinders may also be used. The fluidicmeans 39 is located in the closure means 16 and includes an air inletport 41, a cylinder 42, a displaceable piston 43 and a resilient O-ringair seal 44 seated in and retained by annular groove 45 formed in piston43. The fluidic means 40 is located in the closure means 17 and includesan air inlet port 47, a cylinder 48, a displaceable piston 49, and aresilient O-ring air seal 50 seated and retained in annular groove 51 ofpiston 49. The cylinders and pistons of each of the fluidic means 39 and40 are fabricated from any suitable structurally strong and wearresistant material such as metal and the like. The piston 43 of fluidicmeans 39 is biased against the stationary shaft 31 by an elevated airpressure in the fluidic means 39 acting on the piston 43 to bias thepiston into engagement with one extremity of the shaft 31. The piston 49of the fluidic means 40 is biased against the shaft 31 by an elevatedair pressure in the fluidic means 40 acting on the piston 49 to bias thepiston into engagement with the opposite extremity of the stationaryshaft 31. It is seen that the shaft 31 biases the back-up roller 19 intoengagement with the cutter roller 24 in proportion to the air pressureacting upon the pistons 43 and 49. The greater the air pressure actingupon the pistons 43 and 49, greater the force present at the nip 23between the back-up roller 19 and the cutter roller 24. The air pressuresupplied to the fluidic means 39 and 40 is such that the roving to becut is firmly gripped between the engaging portions of the back-uproller 19 and the cutter roller 24 so as to cut the roving into thedesired uniform length without having frayed extremities.

The amount of elevated air pressure in the fluidic means 39 and 40 canbe regulated by a suitable air pressure regulation means (not shown)connected to glass roving fibers 12 of the fiber cutter is accom.-,

plished by releasing the elevated air pressure from fluidic means 39 and40. The shaft 31 and its back-up roller 19 are no longer biasedpermitting a user to remove the glass roving fibers 12 from the cutterl0-by moving the back-up roller 19 away from the cutter roller 24 withlittle effort and pulling the roving fibers out of the cutter. New ordifferent fibers 12 can be loaded into the cutter 10 without usingadditional means ,to assist in inserting such fibers between thepressure roller 20 and the back-up roller 19 and between the back-uproller 19 and the cutter roller 24. To load the cutter 10, a userthreads the fibers 12 through the apertures 57 and 58 and then'betweenthe pressure roller 20 and the back-up roller 19 to an area adjacent thecutter roller 24. The user then manually rotates the cutter roller 24 byrotating knurled end 54 of shaft 21. The manually rotated blades 29 ofthe cutter roller 24 tend to guide the roving fibers 12 into the spacebetween the spaced apart back-up roller 19 and the cutter roller 24toward the ejection opening 25 thereby loading the cutter 10. Applyingair to the drive motor and to the fluidic means 39 and 40 renders thecutter l0 operational.

Using spring means to bias the back-up roller requires that the back-uproller be moved with sufficient force to overcome the biasing action ofthe spring whereas removing the elevated air pressure from the fibercutter 10 requires that the user only overcome the gravitational forceexerted onthe back-up roller 19 to load or unload the fiber cutter.

The start-up torque of the fiber cutter 10 is less than that required bya spring biased fiber cutter, since the backup roller 19 of cutter 10 isnot fully biased at the time rotation of the cutter roller 24 isinitiated whereas in a spring biased cutter, the biased roller is fullybiased at the time rotation of the rollers of the cutter is initiated.

Preferably, the drive motor 15 is a pneumatic or air motor, although itshould be appreciated that the drive motor may be any other suitabletype. An air operated drive motor is preferred inasmuch as compressedair is also employed to bias the back-up roller 19 into engagement withthe cutter roller 24 so as to compensate for wear experienced by thefiber cutter 10 during its operation. The structure of the fiber cutter10 is described with the cutter roller 24 being motor-driven, however,it should be understood that the back-up roller 19 may be driven by thedrive motor 15 instead of the cutter roller 24.

Referring again to FIG. 1, the air motor 15 includes an inlet 53connected to the conduit 52 through T- section 55. The air motor 15 isof standard construction, and therefore, in the interest of clarity, thedetails of the air motor have been omitted from the drawing and thisspecification. The drive shaft 26 of the air motor 15 is directlyconnected to the cutter roller 24 to rotatably drive the cutter rollerin such a direction source (not as to ensure that cut roving 13 isdirected toward and out the ejection opening 25 of the fiber cutter 10.

Although not shown, the exhaust of the air motor 15 can be utilized, ifdesired, to assist in guiding the glass roving 112 from the outlet endof the nip 22 defined by the back-up roller 19 and the pressure roller20 and to the inlet end of the nip 23 defined by the back-up roller 19and cutter roller 24. The exhaust air of the air motor 15 can also beused to assist in ejecting the cut roving 13 from the ejection opening25.

Referring again to FIG. 3, means is provided for biasing the rotatablepressure roller 20 into engagement with the back-up roller 19. Thepressure roller 20 is eccentrically mounted on the stationary shaft 36.The pressure roller 19 is fabricated from any suitable wear resistantmaterial such a metal. The shaft 36 has its opposite extremities (notshown) fixedly mounted in the side closures 16 and 117. During operationof the fiber cutter 10, the shaft 36 is retained in fixed position by asuitable locking means 56 shown in FIG. l as a bolt turned onto threads(not shown) formed in one extremity of the shaft 36. Turning the bolt 56so as to allow manual rotation of the shaft 36 by the user permits theuser to displace the pressure roller 20 so as to compensate for possibleinconsistancies in fabrication tolerance of the rollers. Returning thebolt 56 to its initial position on the threads of shaft 36 locks thepressure roller 20 in position with respect to the back-up roller 19.

It will be understood that modifications and variations may be effectedwithout departing from the scope of the novel concepts of the presentinvention.

I claim:

l. A self-adjusting fiber cutter for use with a device for dispensingmaterial, the fiber cutter comprising rotatable roller means, includinga rotatable back-up roller and rotatable cutter roller, a fluid motor todrive the rotatable roller means, means for cutting fiber in the nipinto short lengths carried by the rotatable cutter roller, means forfluidically biasing one of the rotatable roller means into cooperativerelationship with the other rotatable rollermeans to provide a nip andto adjust the cutting pressure of the nip exerted on the fiber duringthe operation of the fiber cutter, and means interconnecting a source offluid under pressure with both the fluid motor and the means forfluidically biasing one of the rotatable roller means.

2. The self-adjusting fiber cutter of claim 1, including pressure rollermeans free to rotate concentrically about an eccentrically mountedstationary shaft.

3. The self-adjusting fiber cutter of claim 1, wherein the means forfluidically biasing one of the rollermeans includes air cylinder meanscomprising movable piston means biasing the one of the roller means intoengagement with the other roller means.

4. The selfadjusting fiber cutter of claim 3, wherein the movable pistonmeans of the air cylinder means bias a shaft carrying the roller meanstoward the other roller means, the other rolier means being fixedlypositioned.

5. The self-adjusting fiber cutter of claim 4, wherein the cutter rolleris rotatably driven by the fluid motor, and the back-up roller is biasedinto engagement with the cutter roller by the movable piston means ofthe air cylinder means.

6. The self-adjusting fiber cutter of claim 5, wherein the shaft of theback-up rolelr means is substantially stationary and retained inelongated slots to be movable in a plane substantially perpendicular tothe axis of rotation of the cutter roller means.

7. The self-adjusting fiber cutter of claim 6, wherein the stationaryshaft includes a flat portion that engages with one of the elongatedslots to retain the shaft in a stationary location.

8. A fiber cutter for ejecting cut lengths of fibers into a spray ofplural component material comprising a back-up roller and a cutterroller in cooperative relationship to provide a nip for the fiber to becut, the cutter roller including means for cutting the fiber in the nipinto short lengths, means to drive the back-up roller and cutter roller,means for fluidically biasing one of the rollers into engagement withthe other roller to adjust the cutting pressure of the nip exerted onthe fiber during operation of the cutter, said driving means and saidfluidically biasing means being simultaneously operable, and a pressureroller free to rotate concentrically about an eccentrically mountedstationary shaft in cooperative relationship with the back-up roller toprovide a nip for the fiber to be cut.

9. The cutter of claim 8, wherein the stationary shaft is adapted to bearcuately displaced to displace the pressure roller from cooperativerelationship with the back-up roller.

10. The cutter of claim 9, wherein the stationary shaft includes meansfor fixedly retaining the stationary shaft in position during cutting ofthe fiber.

1. A self-adjusting fiber cutter for use with a device for dispensingmaterial, the fiber cutter comprising rotatable roller means including arotatable back-up roller and rotatable cutter roller, a fluid motor todrive the rotatable roller means, means for cutting fiber in the nipinto short lengths carried by the rotatable cutter roller, means forfluidically biasing one of the rotatable roller means into cooperativerelationship with the other rotatable roller means to provide a nip andto adjust the cutting pressure of the nip exerted on the fiber duringthe operation of the fiber cutter, and means interconnecting a source offluid under pressure with both the fluid motor and the means forfluidically biasing one of the rotatable roller means.
 2. Theself-adjusting fiber cutter of claim 1, including pressure roller meansfree to rotate concentrically about an eccentrically mounted stationaryshaft.
 3. The self-adjusting fiber cutter of claim 1, wherein the meansfor fluidically biasing one of the roller means includes air cylindermeans comprising movable piston means biasing the one of the rollermeans into engagement with the other roller means.
 4. The self-adjustingfiber cutter of claim 3, wherein the movable piston means of the aircylinder means bias a shaft carrying the roller means toward the otherroller means, the other roller means being fixedly positioned.
 5. Theself-adjusting fiber cutter of claim 4, wherein the cutter roller isrotatably driven by the fluid motor, and the back-up roller is biasedinto engagement with the cutter roller by the movable piston means ofthe air cylinder means.
 6. The self-adjusting fiber cutter of claim 5,wherein the shaft of the back-up rolelr means is substantiallystationary and retained in elongated slots to be movable in a planesubstantially perpendicular to the axis of rotation of the cutter rollermeans.
 7. The self-adjusting fiber cutter of claim 6, wherein thestationary shaft includes a flat portion that engages with one of theelongated slots to retain the shaft in a stationary location.
 8. A fibercutter for ejecting cut lengths of fibers into a spray of pluralcomponent material comprising a back-up roller and a cutter roller incooperative relationship to provide a nip for the fiber to be cut, thecutter roller including means for cutting the fiber in the nip intoshort lengths, means to drive the back-up roller and cutter roller,means for fluidically biasing one of the rollers into engagement withthe other roller to adjust the cutting pressure of the nip exerted onthe fiber during operation of the cutter, said driving means and saidfluidically biasing means being simultaneously operable, and a pressureroller free to rotate concentrically about an eccentrically mountedstationary shaft in cooperative relationship with the back-up roller toprovide a nip for the fiber to be cut.
 9. The cutter of claim 8, whereinthe stationary shaft is adapted to be arcuately displaced to displacethe pressure roller from cooperative relationship with the back-uproller.
 10. The cutter of claim 9, wherein the stationary shaft includesmeans for fixedly retaining the stationary shaft in position duringcutting of the fiber.